Reefscapers Diary December 2021

Coral Propagation – Monthly Progress

At Landaa during December, we transplanted 75 new coral frames (59 guest-sponsored, 10 resort-sponsored, six online) including one incredibly generous sponsorship (with frames organised into a customised pattern). We used a total of 3454 coral fragments this month, and monitored (cleaned, repaired, photographed) a total of 356 frames at various sites around the island.

Due to the strong wave action that has periodically overturned some of our coral frames at Parrot Reef, we have relocated 100 out of 300 frames to a more sheltered area towards the turtle cage (at 4 to 7m depth). Thanks to our team of five volunteers (three on the boat and two in the water) who mastered the ‘hook’ method to great effect.

Annual Totals: at Landaa Giraavaru during 2021, we created 351 new coral frames, recycled 44 old frames, and monitored 3145 frames, adding an impressive total of 18,949 coral fragments back onto the reef.

At Kuda Huraa during December, we transplanted six recycled coral frames and seven new frames, using a total of 621 fragments (from eight different coral species).

Annual Totals: at Kuda Huraa during 2021, a total of 126 coral frames (new and recycled) were transplanted using 6848 coral fragments (from 21 different coral species), and we monitored a further 1028 frames.

• Water Villas (WV) – we relocated 159 frames this month, due to continued sand movement around the lagoon (a total of 933 frames have now been relocated this year). The dolphin frame shape is now under threat, comprising many healthy, mature coral colonies (important for spawning) and harbouring diverse fish and invertebrate populations.
• Blue Hole (BH) – coral colonies remain healthy.
• Channel (CH) – coral frames have been rearranged into lines, simplifying our mapping and monitoring work, and enhancing the aspect for resort guest snorkelling. Some frames have been removed, washed, recoated, and recycled. Some of our retransplanting efforts have been unsuccessful, despite close monitoring and using the most resilient coral species (Montipora digitifera, M. foliosa, Pocillopora damicornis, P. verrucosa, Porites species). Colonies have been lost to disease and overgrowth by algae.
• Sea Star (SS) – our warmest site, with low species diversity and some fish predation, however, the species transplanted here are consistently healthy and seem well-adapted to the conditions.
• House Reef (HR) – currently, the northern area (cool and deep) is our preferred site for newly transplanted coral frames.
• Spa island – this month, we removed the 14 frames from this site, to be relocated or recycled. They presented very few healthy colonies (of Porites cylindrica, Pocillopora damicornis, P. verrucosa).

Echinopora horrida (EHO)
Montipora digitata (MDI)
Pocillopora Meandrina (PME)
Pocillopora verrucosa (PVE)

Coral Plates in Aquarium One (plates KH01, KH02, KH05) and Aquarium Two (plates KH03, KH04, KH06)

• KH01 (Galaxea fascicularis; Acropora species replenished Sep-Dec 2021) – growing and healthy; added new fragments of A. tenuis.
• KH02 (G. fascicularis) – fragments have recovered. The plate was rotated two times this month.
• KH03 (Acropora species, replenished Oct-Dec 2021) – newest fragments are already well-encrusted to the plate; added new Acropora.
• KH04 (Acropora species, mushroom coral; replenished Oct-Nov 2021) – the small mushroom corals have adapted and started to grow.
• KH05 (G.fascicularis) – steady health; plate needs to be regularly cleaned of cyanobacteria.
• KH06 (G.fascicularis) – healthy fragments, fusing and growing. Fast-growing but delicate, requiring high irradiance and good water circulation to thrive. New polyps have started growing, indicating excellent environmental conditions for growth.

Reef Futures Virtual Event

The Coral Restoration Consortium (CRC) hosted a free two-part virtual gathering to disseminate new and interesting content to the world’s coral reef restoration community. We listened to the group’s presentations on the ‘latest advancements in holistic approaches, monitoring techniques, propagation, global coral restoration initiatives and more’ to identify how Reefscapers’ restoration efforts had evolved in comparison to other organisations around the world. An example of what Reefscapers has already identified and been working on over the years is reducing the genetic bottleneck of breeding F1 and F2 genets, by collecting coral fragments from a diverse reef environment encompassing the whole reef situated around the island (including a large depth range). Moreover, we have out-planted over half a million coral fragments to date, at Four Seasons Resorts Maldives, compared with smaller initiatives in other international regions planning to out-plant 10,000 fragments over 10 years.

Interest in Our Work

As a result of our recent exposure in local news sites, we have been in communication with a variety of Maldivian organisations with regards to our Reefscapers research, with particular interest in our coral spawning and settlement work. This has included:

• Mihaaru and Dhauru news websites,
• presenting to the International Ocean Institute,
• meeting with the Maldives Marine Research Institute (MMRI),
• meeting with Maldives University to increase our involvement in Maldivian Reef Ecosystems.

Using AI Technology to Analyse Coral Photographs

In order to identify coral growth and overall volume (since 2017), we have been using our in-house AI technology to analyse our small-sized coral frames (at Kuda Huraa and Landaa Giraavaru). This has revealed a steady increase in volume of both Acropora and Pocillopora species from 2017 to 2021.

 Acropora species

• Volume of growth = 1000 litres (at the start of 2020), increasing to 4000 litres by the end of 2021.
• Overall average survival rate = 88% of coral colonies (most frames show a 95% survival rate).
• Highest growth rates at sites: Dive Site, Blu Deep and Anchor Point.
• This species thrives along reef slopes (Suzuki et al., 2008).

 Pocillopora species

• Volume of growth = 5000 litres (at the start of 2020), increasing to 15,000 litres by the end of 2021.
• Overall average survival rate = 80% of coral colonies (most frames show a 90-95% survival rate).
• Highest growth rates at sites: Coral Trail, Parrot Reef, Turtle, Water Villas, Blu.
• This species thrives in shallow water reefs exposed to strong wave action.